Visual tamper-evident conical screw cap and neck finish

ABSTRACT

A tamper-evident cap is disclosed including a closure member and an annular wall depending outward therefrom to a bottom rim. Annular wall has a flange or sealing member extending inwardly adjacent to the closure member and a plurality of threads spaced apart and helically positioned to cooperate with respective threads of a container neck finish having substantially the same outward shape. A band is circumferentially positioned around and attached to the bottom rim by ties, and includes a pull tab and teeth. The pull tab extends from a part of the band and is preferably positioned within the circumference of the band. The teeth have an inner face angled acutely relative to the rim and being designed fit with the neck finish. A cap in combination with a neck finish having a vertical wall for sealing engagement with the cap annular flange is also disclosed.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to U.S. Nonprovisional PatentApplication No. 12/122,835 filed on May 19, 2008.

TECHNICAL FIELD

The present invention relates to container caps and, more particularly,to tamper-evident caps for containers.

BACKGROUND

Various types of caps exist for removably sealing containers, such asblow-molded or injection molded containers. One such cap has spiralthreads extending along an interior surface which match spiral threadson the exterior of a compatible container neck. The threads enable a“screw-on” placement.

Caps may further provide a tamper-evident means, such as a tear band,that is intended to show evidence if the cap has been tampered with orpreviously removed. Many tear bands fit about the cap diameter andcooperate with ratchet teeth on the corresponding container neck finish.Typically, the tear band has a pull tab that must first be torn and thenremoved to permit the end user to twist the cap off from the neck.However, current cap threads and neck finish engagements are not alwayseffective to prevent the removal of the cap without first tearing thetear band. In such case, a so called tamper-evident cap can be removedfrom and reapplied to a container without leaving any visual evidencethat it has been tampered with.

Other tamper-evident bands, such as “drop bands,” are designed to remainon the container. When the cap is twisted the drop band drops down onthe neck revealing that it has been separated from the cap. However, theband does not always drop down as it should and instead may falselyappear to be connected with the bottom of the cap when it is not.

In addition to failing to provide visual evidence of a tampering, suchconfigurations are not always effective for self-centering the cap onthe container thereby resulting in a potential to cross thread duringthe capping operations. Thus there is a need to provide a tamper evidentcap for containers that attaches and releases with relative ease whilepreventing the cap to be removed without also tearing the tear band andstill providing visual evidence of tearing at point of purchase.

SUMMARY OF INVENTION

In general, one aspect of the present invention is directed to acontainer cap including a closure member having an annular wall taperedor conically depending from the periphery of the closure member. At theother end of the depending annular wall is positioned a tamper-evidenttear-off band. This band is secured to the annular wall by tiesextending about the bottom of the annular wall. The band includes a pulltab and ratchet teeth adapted to cooperatively engage teeth on the neckfinish of the container to which it is fit to prevent removal of the capwithout first removing the band. According to aspects, the pull tab ispositioned within the circumference of the band, and, optionally, has abreak-tie securing it to a part of the band. At least one of the teethhas an inner face at an acute angle relative to the bottom rim.

Another aspect of the invention is directed to a neck finish formedhaving a conical wall that defines an opening therethrough. The wallincludes a first end that is typically open to the outside and adaptedto receive a cap, and a second end that terminates at the containerbody. At the first end there is a vertical wall with a lip extendinginwardly of the wall and preferably outwardly of the plane of theopening to provide a secondary seal when cooperating with a cap of thepresent invention.

In another aspect, embodiments of the invention include a bottle capadapted to cooperatively engage the neck finish. In another aspect, theinvention provides a tamper-evident cap having an outwardly conicalannular wall in combination with a neck finish having substantially thesame angular taper.

In another aspect, the bottle cap is made of a molded plastic that islight in weight.

Other objects, features, aspects and advantages of the present inventionwill become better understood or apparent from the following detaileddescription, drawings, and appended claims of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a top perspective view of a cap according to embodiments ofthe present invention.

FIG. 2 shows an elevation of a cap and a bottle neck finish according toembodiments of the present invention.

FIG. 3 shows a partial sectional view of the cap and neck finish andshown in FIG. 1 taken substantially along line A-A of FIG. 1 accordingto embodiments of the present invention.

FIG. 4 shows a bottom plan view of a cap according to embodiments of thepresent invention.

FIG. 5 shows a top plan view of a cap according to embodiments of thepresent invention.

FIG. 6 shows a enlarged detailed view of an interior portion of the capaccording to embodiments of the present invention.

FIG. 7 shows a bottom plan view of a neck finish according toembodiments of the present invention.

FIG. 8 shows a top plan view of a neck finish according to embodimentsof the present invention.

EXAMPLES OF THE PRESENT INVENTION

As shown in FIG. 1, an embodiment of the present invention includes abottle cap 30 that can be used for sealing a container (not shown). Cap30 has a closure member 31 at one end and an annular wall 32 dependingfrom the perimeter thereof and terminating with a bottom rim 35 at itsother end. Closure member 31 is substantially circular and is designedto cover the mouth or opening in a neck finish 50 of a container 10, asshown for example in FIGS. 2 and 3, and includes depending valve 48. Anannular flange 41 extends circumferentially from the closure member 31along wall 32 at an acute angle relative to the plane of member 31.

A visual tamper-evident band 34 extends around the bottom rim 35 ofannular depending wall 32. In an embodiment, annular wall 32 tapersoutwardly from closure member 31 to band 34 and/or has a generallyconical shape. The degree of tapering or conical structure depends, inpart, on the dimensions of the container, particularly the neck finish,with which the cap 30 is used. In an example, annular wall 32 tapers atan angle of about 5° to about 20°; and, in a specific example, annularwall 32 tapers outwardly to rim 35 at about 8°. In tests involving anapproximately 38 millimeter cap, annular walls having an angle greaterthan above 11° were less effective in providing the advantages of thisinvention. The angle can be further adjusted for a 28 or 48 millimetercap, or other sized cap, as such size is commonly referred to in theindustry. The taper or conical structure of the cap and neck finishpermits the cap to self-center on the neck during the capping process.The cap can be made from plastic such as high or low densitypolyethylene or any other resilient material that is suitable forsecuring a cap to a container.

The visual tamper-evident band 34 includes a pull tab 36, extending froma part of the band 34, and ratchet teeth 39 aligned along an interiorsurface thereof. Band 34 attaches to bottom rim 35 of the annular wall32 with ties 37. Ties 37 extend radially outward from bottom rim 35 ofcap 30 and affix directly to band 34. Ties 37 are positioned generallyhorizontally to maintain alignment of band 34. Ties 37 connect with rim35 sufficient to affix the band thereto while also permitting the bandto be torn from the wall to allow removal of the cap from the neckfinish. In an example, ties 37 are positioned in between ratchet teeth39. Attachment of the ties to the rim 35 cooperates in preventing thecap from being removed from the container 10 without first removing thetear band 34.

Pull tab 36 is positioned within the circumference of the band 34 andattaches continuous therewith at break-tie 38. Optionally, in anexample, a second break-tie joins a top portion of band 34 to the bottomrim 35 of the cap opposite break-tie 38. In an example, the pull tab 36is upwardly or downwardly extending and is generally horizontal along atop surface. In another embodiment the top surface of pull tab 36 isslanted diagonally as shown for example in FIG. 1. Preferably pull tab36 slants upwardly toward the end of band 34 at brake tie 38. Theextension of pull tab 36 in combination with the tapering or conicalstructure of annular wall 32 enables tab 36 to remain generally withinthe same circumference of the band 34 as shown, for example, in FIGS. 4and 5. This placement on band 34 leaves an open space between the wall32 and the tab 36 in which the user can grab hold of the extendingportion of the tab 36 and pull the tab 36 disengaging the break-tie 38from the band 34. The conical shape allows the tab 36 of band 34 to betucked inward toward annular wall 32. Additionally, unlike many priortamper-evident caps which have pull tabs that protrude beyond the band'souter circumference, the present cap is not hindered by such protrusionenabling it to move freely in an orientation roll sorter for positioningand appropriately orienting them for application to a container.Further, such circumferential positioning prevents the cap tabs frominterlocking or entangling with tabs of other caps in the chute orsorter. Working in the 360 degree band circumference gives the cap anopportunity to roll without interference between the cap and orientationprocess.

In an example, a user removes cap 30 by sliding a finger down alongannular wall 32 pushing tab 36 outward, and pulling tab 36 away fromwall 32 and severing break-tie 38 from a portion of band 34. Furtherpulling on tab 36 breaks the connection of ties 37 with the bottom rim35 and enables band 34 to be partially or completely removed from cap30. Absence of break-tie 38 and one or more ties 37 provides the userwith visual evidence that the cap has been tampered with or removed.

Ratchet teeth 39 are adapted to engage teeth 58 on the neck finish 50 ofa container 10, as shown, for example, in FIG. 2. As shown for examplein FIG. 4, the tips or corners of ratchet teeth 39 extend diagonallyinward of band 34 toward rim 35 but do not connect to the rim 35. Eachratchet tooth 39 has an inner face 40. Inner face 40 is positioned at anacute angle a from the plane of cap 10. In an example, angle α is about10° to about 20° and, in another example, angle α is more preferablyabout 15° from the plane of the cap going inwardly. However, angle αcould vary beyond these ranges if a cap having a longer profile isneeded, for example, if a longer annular wall is used. That angledetermination can be made within the scope of this invention by personsof ordinary skill in the art without undue experimentation. Angle α isimportant in the self-centering of the cap on the neck finish. The innerface 40 is designed, in part, to permit cap 30 to expand over an outeredge of the neck finish when being applied to container 10. This helpsto self center the cap on the container from a slight angle inputted bya capping machine to thus provide proper thread engagement.

Cap 30 includes an annular flange 41 positioned on the annular wall 32proximate to closure member 31. Annular flange 41 extends at an angle βrelative to the closure member 31. In an example angle β is in the rangeof about 30° to about 60°. In another example, angle β is about 45°.According to aspects of the invention, inner face 40 and annular ringflange 41 are located and dimensioned to engage and cooperatively securecap 30 onto the neck finish of a container. For example as illustratedin FIG. 3, cap inner face 40 and flange 41 cooperate with an annularflange 59 and an annular lip 57 of the neck finish 50 of a container 10,respectively, when the cap is screwed onto the neck finish. In anexample, the inner face 40 sits between the bottom end of the neckfinish 56 and a protective rim 70 on the container 10.

Several sets of helically spaced threads 43 are positioned on the innersurface of annular wall 32 generally extending from the closure member31 proximate to the annular flange 41 to the bottom rim 35. Each thread43 has a respective lead opening 44 and tail 45. The threads 43 aretapered toward lead openings 44 and tails 45. The conical or taperdesign of annular wall 32 and threads 43 helps allow the cap 30 to selfcenter on the neck finish of a container. Further, the tapered orconical design minimizes the chance that threads would over strip orcross thread. In an example, there are at least five threads 33 each onehaving a thread lead 44 beginning at about 172 degrees around the innersurface of annular wall 32. In a preferred example, threads 43 areinterrupted. In an example, threads 43 extend more than 90 degrees andless than 360 degrees around the inner surface of annular depending wall32. In an example, threads 43 extend around the inner surface about 180degrees. According to an aspect of the invention, threads 43 projectinwardly from annular wall 32 at an angle γ. Angle γ is in the range ofabout 30 degrees to about 90 degrees, and, preferably, angle γ is about60 degrees, plus or minus five degrees.

The cap includes a sealing means is positioned in juxtaposition with theclosure member. An example of the sealing means is annular valve 48depending from closure member 31. Annular valve 48 is positioned at adistance from annular wall 32 that will permit insertion of the topportion of a container neck finish to fit therebetween. In an example,the valve 48 is spaced from an internal surface of the annular dependingwall at a distance that is sufficient to engage an annular lip on theneck finish. In an example, this joinder creates a corner area 47 foraccepting the “updraft” from the top rim of the neck of a container.Typically, the corner area 47 provides a right angle into which the toprim fits sufficiently to create a sealing engagement. In an example,this rim and the top portion of the container neck fit comfortablybetween the annular flange 41 and annular valve 48. The valve 48 extendsto a point near to the start of threads 43. In an example, valve 48includes a taper 49 which facilitates initial engagement of the valve tothe inner periphery of the neck finish of a container opening.

In another example of cap 30, annular valve 48 may be eliminated. Inthis example it will be preferable to also eliminate annular ring valve41. With removal of annular valve 48, and preferably ring flange 41, acircular sealing member or liner, not shown, would be positionedsubstantially with closure member 31 to provide a seal between saidclosure member and opening 53. The sealing member is preferably a diskmade of foils, foam, paper or the like. This example entails anadditional step of the sealing member placement prior to the bottlecapping operation.

In an example, cap 30 has outer ribs or serrations 46 extending alongthe exterior of annular wall 32. Generally serrations 46 extend from theperimeter of closure member 31 to the bottom rim 35. According toembodiments, serrations 46 taper toward the bottom rim 35 and have anouter spine that is substantially perpendicular to the plane of theclosure member 31. In an example, sets of serrations 46 are positionedequidistant about the circumference of annular wall 32. In an example,each set contains two to four serrations. In an example there are eightsets of serrations, the majority of which sets contain about two, andpreferably three, serrations 46. In another example, there are no setsof serrations. Instead, serrations 46 are evenly positioned so that eachserration 46 is equidistant from each neighboring serration 46. In anexample, 16 to 30 serrations 46 vertically line annular wall 32. In apreferred example, there are 24 serrations 46. Serration 46 incombination with threads 43 help to prevent the cap from nesting whenstacked with other caps.

According to aspects of an embodiment, the present invention includes aconical neck finish 50 of a container 10, as illustrated for example inFIG. 2. Neck finish 50 preferably has substantially the same tapered orconical angle of revolution as cap 30. Neck finish 50 includes anannular wall 52 defining therethrough a cylindrical opening 53 having afirst end 54 and a second end 56. First end 54 provides access toopening 53. Near opening 53, a vertical wall 55 and an annular lip 57are provided at the first end of the annular wall 52. Vertical wall 55is positioned substantially perpendicular to the plane of a fittingclosure member 31. Slight variance in the perpendicular is acceptable;however, a significant divergence may prohibit engagement of the cap tothe neck finish. In an example, the vertical wall varies at less thanabout an 8 or 10 degree angle, and, preferably it is perpendicular.Annular lip 57 extends inward from the vertical wall 55 and terminatesat the inner diameter 51 of the container. The inner diameter 51 is alsosituated at the end of the updraft. Preferably the annular lip 57extends inwardly at a slight outward angle from the plane of the firstend as shown in FIGS. 2 and 3.

In an example, when cap 30 is applied to the neck finish 50, annularvalve 48 is spaced apart from annular wall 32 a distance which isrepresented by the difference in the radial distance from the outer edgeof annular wall 32 at its closure end and the center of a container neckopening and the inner edge of the lip 57. The outer diameter of valve 48together with annular flange 41 on the cap enhance sealability of capclosure member 31 by creating pressure on the container neck. In anembodiment, as the valve 48 penetrates the inner diameter 51 pushesinward to opening 53, updraft of 57 deflects inward and vertical wall 55is pushed outward on the neck. Annular flange 41 actuates on the topportion of vertical wall 55 pushing it back thereby creating a secondaryseal.

Positioned adjacent to the second end 56 is at least one set of annularratchet teeth 58 to provide a tamper evident grip for the cap. Ratchetteeth 58 may be positioned around the entire circumference of the secondend 56 of the neck or only a portion thereof. In an embodiment, thereare two sets of teeth 58 positioned about end 56 with a flat wall 69separating them at each end of both. Each set consists of eight totwelve teeth 58, although they need not have an equal number. In anexample, each set has ten teeth. In an embodiment, the teeth 58 of twodifferent sets of teeth 58 are positioned in opposing directions toprevent “backing off” the cap from the bottle neck. Ratchet teeth 58 areadapted to cooperatively engage corresponding teeth 39 on thetamper-evident band 34 positioned on the mating cap 30.

In an embodiment of the invention, an annular ring flange 59 ispositioned substantially adjacent to the plane in which the annularratchet teeth 58 are provided. This flange 59 in cooperation withannular lip 57 provides a means for securing the cap to the bottle. Inan example, the cap snaps over and locks onto the neck finish.

Helically extending between the annular lip 57 and the annular ringflange 59, are at least three threads 64 leading at points 66 andterminating at points 67, adjacent first end 54 and annular ring flange59, respectively. Threads 64 are helically spaced in contiguousrelationship as shown in FIG. 2. In an example, there are five threads64. In embodiments, each thread 64 extends around the circumference ofannular wall 52 at a degree corresponding to that of cap threads 43.

In an example, when cap 30 is applied to the neck finish 50 of acontainer, the threads of the cap contact the top of the threads of thecontainer neck finish before the valve 48 or flange 41 contact theinside dimension of the container. In an example, cap threads 43 engagethe bottle threads 64 before the ratchet teeth 58 engage. The capthreads engage with the rotating of the cap engaging the threads of neckfinish and engaging the cap 30. Valve 48 cooperates with flange 41 toseal contents when lip 57 pushes against the valve during engagement ofthe threads.

The protective rim 70 extends downwardly and outwardly from the ratchetteeth 58. The protective rim 70 protects the tamper-evident band 34 fromintrusion, for example, by an object that could be used to dislodge thetamper-evident band 34 without tearing it and enable the cap to releasefrom the container. The neck finish can be made of plastic such as highor low density polyethylene of any other material suitable for use withthe contents of the container. The material may be the same as that ofthe container.

Cap 30 when used in combination with neck finish 50 of the presentinvention provides a seal that is particularly well suited to standardbeverage containers, such as blow molded milk containers. When properlysealed, air will not penetrate through the container opening. Use of thetamper-evident band 34 with break tie 38 makes it extremely difficult,if not impossible, to tamper with the contents of the bottle withoutindicating evidence thereof on the cap. Use of optional second break-tieprovides a further security seal.

The embodiments of the invention shown and described in the abovefigures are exemplary of numerous embodiments that may be made withinthe scope of the invention. It is to be understood that the detailedembodiments, figures and examples are presented for elucidation and notlimitation. The invention may be otherwise varied, modified or embodiedwithin the scope of the invention as defined in the appended claims.

1. A tamper-evident cap comprising: a closure member and an annular walldepending from the closure member, said wall tapering outward to abottom rim to cooperate with a neck finish having substantially the sameangular taper; an annular flange positioned around an interior surfaceof the annular wall adjacent to the closure member; at least one tieproximate said bottom rim; a band circumferentially positioned aroundthe bottom rim and attached to said at least one tie, wherein the bandincludes teeth diverted inwardly, wherein the teeth are adapted toengage cooperative teeth on the neck finish, each said tooth having aninner face, said inner face being positioned at an acute angle relativeto the bottom rim; and a plurality of threads spaced apart and helicallypositioned on an interior surface of the annular wall extending fromabout the annular flange to proximate said bottom rim.
 2. The cap as inclaim 1 further including a pull tab extending upwardly or downwardlyfrom a part of the band.
 3. The cap as in claim 2 wherein the pull tabis positioned within the circumference of the band.
 4. The cap as inclaim 2 wherein the pull tab is attached to the band with at least onebreak-tie.
 5. The cap as in claim 1 further including an annular valvedepending from the closure member and spaced apart from an interiorsurface of the annular wall.
 6. The cap as in claim 1 further includingserrations on an exterior surface of the annular wall.
 7. The cap as inclaim 6 wherein the serrations taper toward the bottom rim and have anouter dimension that is substantially perpendicular to the plane of theclosure member.
 8. The cap as in claim 1 wherein the flange extendsrelative to the closure member at an angle of about 30 degrees to about60 degrees.
 9. The cap as in claim 1 wherein the threads projectinwardly at an angle of about 30 to 90 degrees.
 10. The cap as in claim1 wherein the acute angle of inner face is about 10 to about 20 degrees.11. The cap as in claim 1 wherein multiple ties extend horizontallyradially from the bottom rim.
 12. The cap as in claim 1 wherein saidangular taper provides a conical shape.
 13. The cap as in claim 1 incombination with a neck finish for a container, wherein the neck finishcomprises: an annular wall having a first and second end, defining acylindrical opening therethrough, and having an annular lip extendinginwardly toward said opening from a vertical wall at the first endthereof; at least one set of ratchet teeth positioned around a portionof an outer surface of the neck annular wall at the second end; andmultiple threads angularly positioned on an exterior surface of the neckannular wall between the first end and the ratchet teeth.
 14. The cap asin claim 13 wherein the vertical wall is adapted to associate or engagethe annular flange on the cap.
 15. The cap as in claim 13 wherein thelip terminates with an inner end adapted to contact a valve of the cap.16. The cap as in claim 13 wherein the neck finish further includes anannular ring flange extending substantially around the annular walladjacent to the set of ratchet teeth.
 17. The cap as in claim 13 furtherincluding a protective rim 70 extending around the exterior surface ofthe neck annular wall and projecting outward from the set of ratchetteeth.
 18. The cap as in claim 13 wherein the cap further includes avalve depending from the closure member spaced apart from an internalsurface of the annular depending wall a distance sufficient to engage anannular lip of the neck finish.
 19. A tamper-evident cap comprising aclosure member and an annular wall depending therefrom, said walltapering outwardly to a bottom rim to cooperate with a neck finishhaving substantially the same angular taper; a sealing memberjuxtapositioned substantially coextensively with said closure member; atleast one tie proximate said bottom rim, a band circumferentiallypositioned mount said bottom rim having teeth directed inwardly and atleast one tooth being mounted on a boss and adapted to engage teeth on aneck finish of a bottle, each of said teeth having an inner facepositioned at an acute angle relative to the bottom rim; and a pluralityof spaced apart threads helically positioned on the inner surface of theannular wall from a point positioned away from said sealing member toabout said bottom rim.
 20. The cap as set forth in claim 19 wherein saidsealing member comprises a disk.